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831.
Chris R. Pavey Chris J. Burwell Gerhard Körtner Fritz Geiser 《Die Naturwissenschaften》2009,96(6):679-683
One of the energetic benefits of daily torpor over prolonged hibernation is that it enables animals to regularly forage and,
therefore, replenish food reserves between bouts of torpor. However, little is known about the diet of predators undergoing
torpor or whether differences in prey composition among individuals influence torpor characteristics. Here, we test the hypothesis
that prey composition affects winter torpor use and patterns of a population of carnivorous marsupial, the brush-tailed mulgara
(Dasycercus blythi), in the Great Sandy Desert, Australia. Mulgaras in the study population captured a wide range of prey including vertebrates
(mammals, reptiles, birds), seven insect orders, spiders and centipedes. The proportion of vertebrates in the diet was negatively
correlated with both frequency of torpor use and maximum bout duration. This variation in torpor use with diet can be explained
by the higher energetic content of vertebrates as well as their larger size. Even assuming uniform intake of prey biomass
among individuals, those that subsisted on an invertebrate-dominated diet during winter apparently suffered energetic shortages
as a result of the scarcity of invertebrate taxa with high energy content (such as insect larvae). Our study is the first
to demonstrate a link between diet composition and daily torpor use in a free-ranging mammal. 相似文献
832.
Götz Schroth Peter Laderach Jan Dempewolf Stacy Philpott Jeremy Haggar Hallie Eakin Teresa Castillejos Jaime Garcia Moreno Lorena Soto Pinto Ricardo Hernandez Anton Eitzinger Julian Ramirez-Villegas 《Mitigation and Adaptation Strategies for Global Change》2009,14(7):605-625
The mountain chain of the Sierra Madre de Chiapas in southern Mexico is globally significant for its biodiversity and is one of the most important coffee production areas of Mexico. It provides water for several municipalities and its biosphere reserves are important tourist attractions. Much of the forest cover outside the core protected areas is in fact coffee grown under traditional forest shade. Unless this (agro)forest cover can be sustained, the biodiversity of the Sierra Madre and the environmental services it provides are at risk. We analyzed the threats to livelihoods and environment from climate change through crop suitability modeling based on downscaled climate scenarios for the period 2040 to 2069 (referred to as 2050s) and developed adaptation options through an expert workshop. Significant areas of forest and occasionally coffee are destroyed every year by wildfires, and this problem is bound to increase in a hotter and drier future climate. Widespread landslides and inundations, including on coffee farms, have recently been caused by hurricanes whose intensity is predicted to increase. A hotter climate with more irregular rainfall will be less favorable to the production of quality coffee and lower profitability may compel farmers to abandon shade coffee and expand other land uses of less biodiversity value, probably at the expense of forest. A comprehensive strategy to sustain the biodiversity, ecosystem services and livelihoods of the Sierra Madre in the face of climate change should include the promotion of biodiversity friendly coffee growing and processing practices including complex shade which can offer some hurricane protection and product diversification; payments for forest conservation and restoration from existing government programs complemented by private initiatives; diversification of income sources to mitigate risks associated with unstable environmental conditions and coffee markets; integrated fire management; development of markets that reward sustainable land use practices and forest conservation; crop insurance programs that are accessible to smallholders; and the strengthening of local capacity for adaptive resource management. 相似文献
833.
834.
In this study the focus is on the continuous ergonomic-focused development of a medical instrument that is capable of performing blood group serological tests. Primarily, a medical device must be clinically effective and safe. At the same time it must also meet the needs of its users. This calls for consideration of numerous ergonomic aspects. The development process of the product line in question was supported by a longitudinal series of carefully designed focus groups. Altogether, the 23 focus groups conducted included 245 participants from 72 laboratories. The aim of the empirical research was to collect users’ experiences, ideas and needs as inputs for the following phase of the product development process. During the mentioned focus group analyses, around 100 development proposals were conceived. Besides presenting more of the mentioned development proposals, the focus group analysis was shown as a proper methodology to involve end-users in the development and implementation of new technology or devices. 相似文献
835.
Anna Elofsson Nora Smedby Jörgen Larsson Jonas Nässén 《Journal of Environmental Policy & Planning》2018,20(5):578-594
Global greenhouse gas emissions from air travel (GHG-A) are on the rise, and projections point towards a rapid growth in the coming decades. This study aims to examine how local government (cities), addresses GHG-A in their Sustainable Energy Action Plans (SEAP). To fulfil this aim, over 200 SEAPs were analysed focusing on three issues: (1) Treatment of GHG-A in local emissions inventories; (2) Policy initiatives within this domain; and (3) The cities’ perceptions of the conflicts of interests. Results showed that more than half of the cities acknowledge the challenge of GHG-A, around one third include GHG-A in their emissions inventories, and more than one quarter have initiated policy interventions. To categorise these interventions, we have added a mode ‘governing by agenda setting’ to an existing analytical framework, ‘Modes of governing’. With their authority limited to the local setting, this mode of governing is a common channel for cities to push changes at higher levels. 相似文献
836.
Per Schubert Nils G. A. Ekelund Thomas H. Beery Christine Wamsler K. Ingemar Jönsson Andreas Roth 《Journal of Environmental Policy & Planning》2018,20(3):298-312
While ecosystem-based planning approaches are increasingly promoted through international and national policies, municipalities are still struggling with translating them into practice. Against this background, this paper aims to increase the knowledge of current advances and possible ways to support the implementation of the ecosystem services (ES) approach at the municipal level. More specifically, we analyze how ES have been integrated into comprehensive planning within the municipality of Malmö in Sweden over the last 60 years, a declared forerunner in local environmental governance. Based on a content analysis of comprehensive plans over the period 1956–2014 and interviews with municipal stakeholders, this paper demonstrates how planning has shifted over time toward a more holistic view of ES and their significance for human well-being and urban sustainability. Both explicit and implicit applications of the ES concept were found in the analyzed comprehensive plans and associated programs and projects. Our study shows how these applications reflect international, national, and local policy changes, and indicates how municipalities can gradually integrate the ES approach into comprehensive planning and facilitate the transition from implicit to more explicit knowledge use. 相似文献
837.
Willie Peijnenburg Lennart Eriksson Arthur de Groot Michael Sjöström Hans Verboom 《Environmental science and pollution research international》1998,5(1):12-16
Disappearance rate constants are reported for the reductive transformation of 17 halogenated aliphatic hydrocarbons in anaerobic
sediment-water samples. Statistical experimental design in combination with multivariate chemical characterization of their
chemical properties was used to select the compounds. Degradation followed pseudo first-order kinetics through at least two
half-lives for 15 of the 17 compounds. Of all the compounds investigated, 1,2,3-trichloropropane and dichloromethane were
unique in that they were dehalogenated according to zero-order kinetics. Reductive dehalogenation was the sole transformation
reaction taking place. 相似文献
838.
Thomas Höfer 《Environmental science and pollution research international》1999,6(2):107-114
This report gives an inside view on discussions held at the headquarters of the International Maritime Organization, the United Nations agency concerned with maritime safety and the prevention of pollution from ships. Marine environmental protection regulations and their historical development are presented and discussed. The regulative measures that have been taken under the responsibility of this organization during the last decades to reduce accidental and operational discharge from tankships have achieved success although the marine environment is still suffering. Those standards which will come into force will further reduce the risks of accidental pollution. The report summarizes aspects beyond issues of environmental science which have to be analysed in order to reduce the impact of tankships on the marine environment. The report ends with the thesis that safer ships and improved occupational conditions on board are prerequisites for cleaner seas. 相似文献
839.
Parental investment, potential reproductive rates, and mating system in the strawberry dart-poison frog, Dendrobates pumilio 总被引:1,自引:0,他引:1
We studied the effect of relative parental investment on potential reproductive rates (PRRs) to explain sex differences in
selectivity and competition in the dart-poison frog Dendrobates pumilio. We recorded the reproductive behavior of this species in a Costa Rican lowland rainforest for almost 6 months. Females spent
more time on parental care than males, and `time out' estimates suggest that PRRs of males are much higher than than those
of females, rendering females the limiting sex in the mating process. Males defended territories that provide suitable calling
sites, space for courtship and oviposition, and prevent interference by competitors. Male mating success was highly variable,
from 0 to 12 matings, and was significantly correlated with calling activity and average perch height, but was independent
of body size and weight. Estimates of opportunity for sexual selection and variation in male mating success are given. The
mating system is polygamous: males and females mated several times with different mates. Females were more selective than
males and may sample males between matings. The discrepancy in PRRs between the sexes due to differences in parental investment
and the prolonged breeding season is sufficient to explain the observed mating pattern i.e., selective females, high variance
in male mating success, and the considerable opportunity for sexual selection.
Received: 9 June 1998 / Received in revised form: 27 March 1999 / Accepted: 3 April 1999 相似文献
840.
A general and intuitive prediction from models of mate preference is that when the cost of searching for mates increases,
individuals should become less choosy. Here, we test this prediction by comparing the mating propensity of females in two
populations of the butterfly Pararge aegeria. The populations originated from southern Sweden and Madeira and due to different adult emergence patterns throughout the
year, the average density of males per female is likely to be lower on Madeira. Therefore, we expected that the cost of searching
should be greater on Madeira and, consequently, that the Madeiran females should be less choosy. In line with predictions,
the Madeiran females mated significantly sooner after the first interaction with males than did females from southern Sweden.
This difference may reflect a weaker preference for territorial males over non-territorial patrollers in the Madeiran population,
because of the greater costs of searching. The Madeiran females also showed a shorter time lag between mating and the start
of oviposition. We discuss this unexpected result and propose that the same mechanism could also explain this population difference,
i.e. different costs of searching for suitable host plants. Both search processes are fundamental for female reproductive
success and we find it plausible that they can be generalised into the same theory of optimal search behaviour.
Received: 14 May 1998 / Accepted after revision: 13 December 1998 相似文献